Firefox64

I had a slight break in the rain last night and had a chance to swap out the cap and rotor between my truck and another truck. My cap and rotor ran with the other truck and his did not run on my engine.

I'm going to pull the wires and recheck them next.

Thanks, guys...

Mark

kevinkpk

Try the plug wires off the running truck.

Firefox64

Had a break in the weather today and had a chance to work on the truck today. I swapped out the plug wires with another truck and no change. The other truck ran fine on my wires and no start with mine. More frustration. I must be overlooking something really simple......

Mark

Firefox64

Well, I spent some time today trying to figure out this thing. Just to summerize, I have new spark plugs, new spark plug wires, new cap and rotor, new coil, tested and verified ICM, tested and verified cam sensor, tested and verified crank sensor, good plug connectors, inspected wiring ( didn't find any issues ), good fuel pressure and wet plugs when cranking. Truck has run with incorrectly gapped spark plugs ( .035 ) and ran fine. Properly gapped plugs ( .060 ) will not start. It will give a little huff when key is released after cranking. Good battery and good voltage at coil.

I need a drink.

Mark

Joe In NY

hmmm. strange. well the 5.3's call for .04 gap. I would try that and if it runs, and runs good leave it at that. i mean .06 is a decent gap for a gm motor. Dodge hemi's run .055 to .06 and they have 2 plugs per cyl and a higher voltage ignition, more advanced than gm's simple ignition....

a55bruce

When you swapped the plug wires from the other truck, did you swap the coil wire too? Try checking the ground connection of the coil. IIRC there was a discussion about shims under the crank sensor.

Firefox64

Good morning, guys and gals...

When I swapped out the wires I did also swap out the coil wire. I also checked the resistance again and they are good.

As for the crank sensor, I am going to focus on that and go through everything. I had heard about a shim issue and I'm going to try to figure that out. I had swapped in three known good sensors without change and with the truck starting and running with improper gap I'm thinking that the sensors aren't the issue.....unless the wider gap is causing a power draw in the system that's changing something? Possible?

Mark

Firefox64

I'm also going to go over the entire ground setup again........

Thanks for the input guys. Someday we'll figure this thing out.

Mark

Stephen Bannworth

Is there good gas, maybe water in the tank?

Firefox64

The gas should be good. It was filled up in February and still has 3/4 tank. The truck has run with the improper gap and when it ran it was strong and not stumbling so I'd expect that the fuel is fine.

I didn't get a chance to play with the truck yesterday but today is another day...